Art of transmitting sounds by means of hertzian waves.



W. HARRISON.

ART OF TRANSMITTING SOUNDS BY MEANS OF HBRTZIAN WAVES.

APPLICATION FILED JUNE 2, 1902.

Patented Dec. 29, 1914.

a7 llllllll. M

5 m a x 2 f 5v L m 7 :4, .2 z x z I awvewtoz flaw.

UNIT D STATES PATENT oiuucn WALTON HARRISON, OF NEW YORK, N. Y.

ART OF TRANSMITTING SOUNDS BY MEANS OF HERTZIAN WAVES.

Specification of Letters Patent.

- Patented Dec. 29, 11914.

Application filed lane 2, 1902. Serial No. 109,847.

- there are certain forms of apparatus which I prefer to use connection therewith. In

the accompanying drawing, forming a part of this specification, and in WhlCh like letters indicate like parts, one such form 1s Figure 1 is a. diagram, showing a wireless transmitter, through the agency of Whichmy art may be employed; Fig. 2 1s adiagram of one form of wireless receiver which may be used in connection with the-transmitter shown in Fig. 1.

A vibratory diaphragm (1-), is mounted in the mouthpiece .(2), and is highly polished. A lens (3), is so arranged soas to throw a strong light upon the diaphragm, Adjacent to the diaphragm is a conical re- Hector (A), preferably of metal, highly polished. Focused centrally within the' reflector is a-selenium rheostat (5), the terminals of which are the wires (6, 7), wherebattery (8), and also with by the selenium rheostat is connected with a the primary coil (9) of a transformer (10). The lens, diaphra'gm, reflector, selenium rheostat, battery and wires; practically constitute a modification of Bells -photophone'.

The secondary coil (11) of the transformer (10) is, by means of wires (12,13), connected with an oscillator consisting of .the polished knobs (14, 15), these Imobs being connected respectivelyiwith the capacities (16, 17) by means of the wires (18, 19) and adjustably supported. upon posts (20, 21). This oscillator is used in generating Hertzian waves in the usual manner,

and 1s energized by the secondary coil (11).

rotary coherer, Such are enlarged and fitted into? as:

V which they (4), the rays are focused upon the air amp The receiving instrument for detecting g the Hertzian waves. may employ an ordinary as is shown in Fig. 2. The coherer tube (22) is fitted .with manna tionary metal cup-like bearings (27, 28). The metallic wings (29-, 30), are connected with rods (31, 32), upon which the bearings are supported. The rods (31, 32) are by means of wires (33, 34) connected with the impedance coils (35, 36), the battery (37) and the telephonic receiver (38). The space between the disks" (23, 24) is partially filled with metallic filings (39) and the coherer tube is rotated by gearing (4:0) for the purpose of decohering other suitable form of Hertzian wave detector may be used instead of the apparatus shown in Fig. 2.

The operation of the mechanism shown in Figs. 1 and 2 is as follows: Ordinary light rays pass through the lens (3) and are concentrated upon the-diaphragm (1), from are reflected upward; striking the internal surface of the conical selenium rheostat. Normally the selenium rheostat has great electricalresistance, but when illuminated its resistance is lowered, as in Bells photophone lf now, sounds are produced adjacent'to t e mouthpiece (2), thus causing the diap ragm (1) to vibrate, the quantity of light, enteringthe reflector and concentrated upon the rheostat is varied Any the filings, in the manner usual with rotary coherers.

therefore energized by virtually intermittent currents of short duration. These currents are in many respects quite analogous to sound waves. The currents of course virtually intermittent passing through the primary coil, induce intermittent but morepowerfnl currents through the secondary coil.)

course,

(11). These induced currents are, of alternating in direction as is thecase with induced currents now universally employed in ordinary Bell telephones, but are far more powerful according to the strength of battery- (8). one-of the between the knobs, propagating Hertzian-waves. The Hertzianvwaves' ass through space and strike the Wings 0 .the

coherer, varying the resistance of the current 'flow through the Ire-1 'ce1ver'( 38), causing the same to'emitsounds;

at the eoherertabe (22) eases- Z (39) and thereby varying the ing from the battery (37) The rotation Tim They surge back and forth from capacities to the; other across the the filings to decohe're and the impedance.

gizedby a battery of several volts at least, is capable of handling comparatively heavy currents, and of producing rapid and substantial variations in the power thereof. In effect, therefore, it constitutes a'very ethcient form of interrupter, capable of inducing powerful spark discharges analogous to those of a Ruhmkorfi coil. It follows, as a necessary consequence, that ordinary sounds such as that of the voice, may thus directly control the production of Hertzian waves, and that these waves, thus produced, have impressed upon them a certain arbitrary, 'undulatory character, analogous to that of sound waves; and that they vary in strength and character according to the strength and character of the sounds whereby they are controlled. The oscillatory character of the spark need not be brought into the discussion, because, owing to the high frequency of the oscillations, their individual efi'ect is not perceptible.

The coherer is exceedingly sensitive when used .in connection with a telephonic receiver and a delicate battery for the purpose of detecting slight variations in the strength and character of Hertzian Waves, and the matter of sudden decoherence is of less importance in wireless telephony than in wireless telegraphy. The reason, I suppose, is that when the filings cohere, they are necessarily subjectedto more or less mechanical or molecular stress, and therefore, owing to their elasticity, have a slight 4o tendency to decohere automatically. After being affected by each ,Hertzian wave, therefore, they tend individually to resume their normal shapes. The slight decoherence thus automatically produced, while perhaps use- 45 less for wireless telegraphy, is suflicient to affect-the telephonic receiver. According to Galiotfthe variations of an electric current necessary to produce the audible noises in the telephonic receiver, may be of the order 50 of hundred thousandths of an ampere. The eifect is improved, however, by mechanical decoherence due torotation. Within certain very narrow; limits, the coherer responds quantitatively to the waves.

, The expression Hertzian. waves is herein used in its broad sense, including not only the electro-magnetic phenomena discussed by the late Heinrich Hertz, but all modifications thereof used in. wireless telegraphy, whether aerial, subterranean or submarine.

Claims: v v V 1. The art, herein described, of transmitting sounds by. means of Hertzian waves; which consists in sending an electric ourrent through a substance, the electrical coni sound-controlled flashes of light 'and enerductivity of which is influenced by light, exposing said substance to the action of light, causing sound waves to intermittently vary the quantity of said light to which said substance is exposed, causing said electric current to control the production of Hertzian waves, and causing said waves to control the production of distant sounds.

ing the secondary circuit to induce an oscillatory static discharge, thereby propagating Hertzian waves, and causing said Hertzian waves to control the production of sounds at a distance.

3. The art,'herein described, of transmitting sounds by means of Hertzian waves; which consists in sending an electric current through selenium, subjecting said selenium to varying quantitiesof light forthe purpose of-modifying said current thus passing through the .same, causing the current thus modified to control the propagation of- Hertzian waves correspondingly modified,

and causing said waves, thus modified, to

control thep'roduction of soundwaves at a distance. I 4:. The art, herein described, of transmitting sounds by means of Hertzian waves; which consists in sending an electric current through a substance the electrical resistance of which is influenced by light, subjecting said substance to the action of varying quantities of light for the purpose of modifying said current, causingsaid current thus modified to energize a primary air cuit, causing said primary circuit to energize a secondary circuit, thereby producing Hertzmn waves. and causing said waves to control the produc ion of sounds at a dis-- tance.

5. The art, herein described, of transmitting sounds by means of. Hertzian waves;

which consists in producing an electric current, causing ordinary light to vary the strength thereof, nextproducing mechanical sound vibrations, causing the same to modify the effect of said light upon said current, thereby producing variations analogous to sound waves in the flow of said current, then causing said current to induce a static discharge, next-generating Hertzian waves by aid of said discharge, and finally causingsaid Hertzian waves to control the production,

at' a distance, of sounds simulating those first produced.

6. The art, herein.described,of transmitmittingly vary the time similar to mzasea ting sounds by means of Hertzian waves; which consists in producing sounds, causing the same togovern the production of intermittent flashes of light analogous to sound waves, causing said flashes of light to inter- ,normal strength of an electric current, causing said current, thus affected, to induce electrical surgings in a separate circuit, thereby propagating Hertzian waves having impressed upon them an arbitrary ,undulatory character independent of the oscillatorycausing said Hertzian waves, thus impressed, to control the production of sound'vibrathose first produced.

7 The art, herein described, of transmitting sounds by means of Hertzian Waves; which consists in producin sound-controlled intermittent flashes 0 light, causing the same to virtually interrupt the flow of a current in a primary circuit, causing said current to induce electrostatic surgings in a secondary circuit, thereby propagating Heitzian Waves, and causing said Hertzian waves to control the production ofdistant sounds. a

8. The art, herein'described, of transmit ting sounds by means of Hertzian waves; whlch consists in causing an electric current to pass through a medium ofieringthereto a variable resistance controllable'by light, subjecting the same to the action of light, causing sounds to control the distribution of light afl'ecting said medium, causing said electric current to inducea secondary current capable ofgenerating Hertzian waves, and causing said Hertzian waves to control the production of sounds at a distance.

9. The art, herein described, of transmitting sounds by means of Hertzianwa'ves;

which consists in shedding light upon a medium having an electrical conductivity controllable thereby, causing sounds to con- '-trol the quantity of light thus aifecting said conductivity, rent through said rent, while passlng a primary curmedium, causlng said curgenerating Hertzian waves, and causing the Hertzian .waves from said circuit to control the production of sounds at a distance.

character thereof, and c ting sounds passing through said medium, to act inductlvely upon a circuit capable of I 10. The art herein described of transmitting sounds by means of Hertzian waves;

which consists in causing said sounds to control the angular trical conductivity of a medium sensitive thereto, causing an electric current to flow through said medium and to have its energy controlled thereby, causing said electric current to produce other electric currents by induction and causing said other electric currents to produce oscillatory discharges across a spark gap thereby generating-Hertzian waves impressed with undulations analogous to said sound Waves, causing said Hertzian waves to travel to a distance and affect the resistance of an electric circuit,

'and causi'ng said' electric circuit to control the production of sound waves.

11. The art, herein described, of transmitby means of electromagnetic waves, which consists in generating electromagnetic waves by aid of two interdependent circuits, one of which is controllable by sound Waves and is provided with a por-' .tion sensitive to light, the other being adapted to radiate saidwaves, and causing said waves to control the production of sounds at adistance. V

12. The art, herein described, of transwaves, which consists in generatin electro magnetic 'waves by aid of two inter egendent.

circuits, one of which is inductively ependout upon the other, one of said circuits being controllable by sound waves and provide with a portion sensitive to light, the other being provided with a gap across which electricity flows incidental to the formation of "v'vAL'roN'arson.

i Witnesses:

.- Tnos. H'. Hm

Enw, J. MGNAMARA.

direction of light waves, causing said light waves to vary the elecmitting sounds by means of electromagnetic 

